Monoazo dye.



UNITED STATES PATENT} OFFICE.

HUGO JAESSCHIN, OF BEBL' FI, AND OSKAR KALTWASSER, OF DESSAU, GERMBNY, ASSIGNORS T0 ACTIEN GE SELLSCHAFT FTl'R ANILIN FABRIKATION, OF 'BERLIN,

' GERMANY. v

MONOAZO DYE.

No brewing.

Specification of Letters Patent. Patented Sept. 12, 1911. Application filed May 1, 1911. Serial No. 624,513. I i i To all whom 'it may concern:

Be it known that We, HUGO JAESSCHIN and OSKAR KAL'rwAssEn, subjects of the Emperor of Germany, residing at Berlin, Germany, and Dessau, Germany, our post-oilice addresses being Spenerstrasse 6, Berlin, Germany, and Leopoldstrasse 11, Dessau, Germany, have invented certain newand useful Improvements in Monoazo Dye, of which the following is a specification.

Our invention relates to the manufacture of a new monoazo-dye which produces on Wool from an acid bath after chroming on the fiber violet shades of very good fastness and Which also may serve for production of violet lakes of a remarkable resistance to the actionof light. This new dye is a combination product of diazotized 4-chloro-2- aminophenol-G-sulfonic acid with 2-naph: t-hol-3-carboxylic acid and may be obtained as follows, but theinvention is not confined to this example. The parts are by weight:

Example: 22.6 parts of t-chloro-Q-amino lphenol-(i-sulfonic acid are diazotized in nown manner bymeans of 28 parts of hydrochloric acid of 20 Baum and the diazo compound thus obtained is combined with an aqueous solution of 20 parts of 2- naphtho1-3-carboxylic acid and 30 parts of calcined sodium carbonate. When the combination is complete the dye is salted out,

of soda lye or an acid. In concentratedsulfuric acid it dissolves to abluish-red solution, from which on addition of'ice redbrown' flakes of the, dye areseparated. It

dyes wool from an acid bath after chroxning violet shades. By action of strong reducing agents the dye is split up yielding 4-chloro- 2-aminophenob6-s'ulfonic acid and l-amino- 2-naphthol-3-carboxylic acid.

The dye may be transformed into lakes in" the usual manner by precipitating the aqueous solution of an alkali salt of the dye with a suitable metallic salt, such as barium chlorid, for instance in presence. of a Subf stratum.

Now What We claim is,

As a new article of manufacture the new.

monoazo-dye adapted for the production of violet lakes and dyeing wool from an acid bath after chroming on the fiber violet shades, which dye may be obtained by cornbining diazotized 4-chloro-2-aminophenol:6

sulfonic acid with 2-naphthol3-carboxylic acid and which dye forms in .the dry and 'pulverized shapeof its sodium salt a bluish- I black powder, soluble in water to a claret solution, being unaltered byaddition of sodium carbonate, butassuming a more red; dish coloration onaddition of soda-lye or an acid, soluble in concentrated sulfuric acid to a bluish-red solution, from which on ad; dition of ice red-brown flakes of the dye are separated and being split up by action of strong reducing agents yielding 4;-ch1oro -2- aminophenol-6-sulfonic acid and --la.mino-2- naphthol-3-carboxylic acid;

In testimony whereof We have hereunto set our hands in presence of two subscribing 

